Why Google got a bargain with the admob acquisition

So admob just announced they've been acquired by Google for $750m.  In my view they got a bargain:

• admob is easily the biggest mobile ad network out there in terms of overall scale
• in particular, admob has the best position in terms of the iphone (scale of inventory)
• admob has the best data on the mobile internet and iphone app ecosystem through its admob metrics and admob analytics services
• admob has invested in developing new types of ad units e.g. those that use location etc
• admob is strong in the key US and European markets 
• the company has a great team - all the senior people at admob i have met are decent people who really know their stuff
• google has been comprehensively out-innovated and out-performed by admob, so they need to acquire them to catch up in mobile ads

Welovemobile have a good post on the subject here

In some ways I am disappointed that admob didn't manage to make a $1bn exit - I really think they could have built the business to that type of scale.  I'd speculate the reasons why they didn't hang on for more are:

• Falling click through rates for mobile advertising as consumers become banner blind to mobile display ads, the same as on the web
• Proliferation of other types of ad networks and ad aggregators in the market 
• Some strong competitors in particular regions e.g. Inmobi in India
• Big brands etc slower to move spend into mobile than expected due to the credit crunch, over-reliance on low quality advertisers (casino etc)

If I were Google I would follow this up with another acquisition of one of the other ad networks which is stronger in the other markets admob has not focused on e.g. buzz city or inmobi.   I wouldn't be surprised if they also acquired one of the premium ad networks e.g. Quattro Wireless either. 

Anyway, great job by admob - they really deserved this win.